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the linkage between atoms or radicals of a chemical compound, or the symbol representing this linkage and indicating the number and attachment of the valencies of an atom in constitutional formulas, represented by a pair of dots or a line between atoms, e.g., H—O—H, H—C≡C—H or H:O:H, H:C:::C:H.
coordinate covalent bond a covalent bond in which one of the bonded atoms furnishes both of the shared electrons.
covalent bond a chemical bond between two atoms or radicals formed by the sharing of a pair (single bond), two pairs (double bond), or three pairs of electrons (triple bond).
disulfide bond a strong covalent bond, —S—S—, important in linking polypeptide chains in proteins, the linkage arising as a result of the oxidation of the sulfhydryl (SH) groups of two molecules of cysteine.
high-energy phosphate bond an energy-rich phosphate linkage present in adenosine triphosphate (ATP), phosphocreatine, and certain other biological molecules. On hydrolysis at pH 7 it yields about 8000 calories per mole, in contrast to the 3000 calories yielded by phosphate esters. The bond stores energy that is used to drive biochemical processes, such as the synthesis of macromolecules, contraction of muscles, and the production of the electrical potentials for nerve conduction.
high-energy sulfur bond an energy-rich sulfur linkage, the most important of which occurs in the acetyl-CoA molecule, the main source of energy in fatty acid biosynthesis.
hydrogen bond a weak, primarily electrostatic, bond between a hydrogen atom bound to a highly electronegative element (such as oxygen or nitrogen) in a given molecule, or part of a molecule, and a second highly electronegative atom in another molecule or in a different part of the same molecule.
ionic bond a chemical bond in which electrons are transferred from one atom to another so that one bears a positive and the other a negative charge, the attraction between these opposite charges forming the bond.
peptide bond the —CO—NH— linkage formed between the carboxyl group of one amino acid and the amino group of another; it is an amide linkage joining amino acids to form peptides.
chemistry the force holding two neighboring atoms in place and resisting their separation; a bond is electrovalent if it consists of the attraction between oppositely charged groups, or covalent if it results from the sharing of one, two, or three pairs of electrons by the bonded atoms.
Social medicine A binding force or influence; a cause of union; a uniting tie—e.g., bonds of fellowship
chemistry The force holding two neighboring atoms in place and resisting their separation; a bond is electrovalent if it consists of the attraction between oppositely charged groups, or covalent if it results from the sharing of one, two, or three pairs of electrons by the bonded atoms.
- the force of mutual attraction that holds atoms together in molecules (see VAN DER WAALS INTERACTIONS and SULPHUR BRIDGE), such as high-energy bonds in ATP, weak hydrogen bonds in DNA, PEPTIDE BONDS and the disulphide bond of proteins.
- also called pair bond . The attraction which maintains a male/female relationship, for purposes of breeding, during the life cycle of some animals, mainly warmblooded vertebrates.
chemistry the force holding two neighboring atoms in place and resisting their separation.